Lawsonia inermis, ext.

Endpoint summary

Description of key information

The results of a Buehler test suggest that Lawsonia inermis exhibited no potential to induce dermal sensitization in Guinea pigs under the conditions used.

Active substance, Lawsone; studies on sensitisation are equivocal.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

other: SCCS/1511/13

Adequacy of study:

key study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

Using available in vivo data. LLNA- method was not available in 1990.

Specific details on test material used for the study:

Guideline:OECD 406
Species/strain:
Guinea pig/Dunkin Hartley
Group size:
Main study: 10 female animals in the control, 20 female animals in the test groups
Test substance: Henna Rot , Lawsonia Inermis Leaf Powder
Batch: 830.72
Purity: /
Route: Occlusive epicutaneous induction (50%) and challenge (50%)
Carrier: Petrolatum
GLP: Yes
Date: 1990

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

One group of 20 animals received induction exposures of 0.5 ml at a concentration of 50% in petrolatum on the left flank on absorbent lint (approximately 15 mm x 35 mm) after removal of hair. The occlusive dressing was kept in place for 6 hours and the induction was repeated on the same site on days 7 and 14 for a total of three 6 h exposures. The skin was carefully examined approximately 24 h after each induction on days 1, 8 and 15.

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

Induction exposures of 0.5 ml at a concentration of 50% in petrolatum on the left
flank on absorbent lint (approximately 15 mm x 35 mm) after removal of hair.

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

0.5 ml test material (50% in petrolatum)

Adequacy of challenge:

not specified

No. of animals per dose:

20

Details on study design:

The sensitizing property of the test substance was evaluated in a Buehler delayed contact hypersensitivity study using female albino Hartley guinea pigs. One group of 20 animals received induction exposures of 0.5 ml at a concentration of 50% in petrolatum on the left flank on absorbent lint (approximately 15 mm x 35 mm) after removal of hair. The occlusive dressing was kept in place for 6 hours and the induction was repeated on the same site on days 7 and 14 for a total of three 6 h exposures. The skin was carefully examined approximately 24 h after each induction on days 1, 8 and 15.
Challenge was performed on day 28 by application of 0.5 ml test material (50% in petrolatum) on an area of about 15 mm x 30 mm on the right left flank clipped free of hair held under occlusion for 6 h. Approximately 24 and 48 h after removal of the occlusive dressing, the skin reaction was evaluated and scored using a four-point scale. The individual reactions to the tests substance preparation at the challenge sites were compared between control and test animals.

Positive control substance(s):

not specified

Positive control results:

not specified

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Challenge was performed on day 28 by applic ation of 0.5 ml test material (50% in petrolatum) on an area of about 15 mm x 30 mm on the right left flank clipped free of hair held under occlusion for 6 h.

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Staining caused by the test substance preparation was observed after removal of the occlusive dressing. The study authors considered that this did not prevent evaluation of the treated skin in respect to erythema formation.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Challenge was performed on day 28 by applic ation of 0.5 ml test material (50% in petrolatum) on an area of about 15 mm x 30 mm

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Staining caused by the test substance preparation was observed after removal of the occlusive dressing. The study authors considered that this did not prevent evaluation of the treated skin in respect to erythema formation.

Interpretation of results:

GHS criteria not met

Conclusions:

Staining caused by the test substance preparation was observed after removal of the occlusive dressing. The study authors considered that this did not prevent evaluation of the treated skin in respect to erythema formation. No treatment-related reaction was noted on the treated skin in any animals (0/20)
The results suggest that Lawsonia inermis exhibited no potential to induce dermal sensitization in Guinea pigs in the Buehler test under the conditions used. However, skin staining may have compromised evaluation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Not classified skin sensitisation. The results of a Buehler test suggest that Lawsonia inermis exhibited no potential to induce dermal sensitization in Guinea pigs under the conditions used.